Frame for a vehicle

ABSTRACT

A frame for a vehicle with at least two longitudinal members (8) and at least one wheel shaft (5) supported on suspension members (6) that are fixed to the longitudinal members (8). The longitudinal members (8) are made of composite material and various parts of the frame are glued together.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention concerns a frame for a vehicle, which frame comprises atleast two longitudinal members of composite material, at least one axlesupported by suspension members, and a connection device connecting eachsuspension member to a longitudinal member.

2. Description of the Related Art

The vehicle disclosed concerns a drawn vehicle as well as a self-drivingvehicle, both with at least one axle on both ends as with at least oneaxle on the rear end only.

In particular, the invention concerns, however not exclusively, atrailer with one or more axles on the rear end.

With such frames, the longitudinal members are made of metal, usuallysteel.

Longitudinal members of steel are relatively heavy, as a result of whichalso the frame is relatively heavy.

That is why frames with longitudinal members made of aluminum arealready used. They are lighter but relatively expensive. In order tooffer the same bending strength and torsional strength as steel,aluminum struts must have a larger section.

Recently, frames with longitudinal members of composite material--i.e.synthetic material reinforced with fibres have been experimented.

Such frame is disclosed in the article of GERALD L. MAY: "Compositetruck frame rails tested" in AUTOMOTIVE ENGINEERING, vol. 87, no. 11,November 1979, pages 77-79.

SUMMARY OF THE INVENTION

The invention discloses a frame which does not have the above mentionedand other disadvantages of the prior art, and which has a greaterstrength than that of the prior art, but is nevertheless relativelylight in weight and inexpensive.

This aim of the invention is achieved by a connection device comprisinga connecting piece (what is called a trestle) which is inserted with itsupper end inside a longitudinal member, whereby two standing side wallsof this end are glued to parts of the longitudinal member.

Preferably, the longitudinal members are composed of members comprisingtwo base struts, the upper end of the trestle being inserted betweensaid base struts and glued to both base struts.

According to the invention, the aim is also reached in that thelongitudinal members are composed of members comprising two base strutswith a U-shaped section, which are directed with their cores to oneanother and which are connected to one another by at least two smallerconnecting struts which are glued to the cores of the above-mentionedbase struts.

According to another aspect of the invention, the frame comprises atleast one cross member which is made of a composite material and whichis glued, for example by the intermediary of a flange or by athickening, to the longitudinal members with its end and comprises atubular body made by pulwinding or filament winding.

The frame may comprise at its front portion a plate made of a compositematerial which is glued to the two longitudinal members and whichcarries the king pin at the bottom for fastening it to a trailer.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better explain the characteristics of the invention, thefollowing preferred embodiment of a frame according to the invention isdescribed as an example only without being limitative in any way, withreference to the accompanying drawings, in which:

FIG. 1 shows a truck with a trailer according to the invention;

FIG. 2 shows the part which is indicated by F2 in FIG. 1 to a largerscale;

FIG. 3 shows the section according to line 111--111 in FIG. 2 inperspective;

FIG. 4 shows a view according to F4 in FIG. 3;

FIG. 5 shows a section according to line V--V in FIG. 3;

FIG. 6 shows a side view of a part of a trailer analogous to that inFIG. 2, but with reference to another embodiment thereof;

FIG. 7 shows a section according to line VII--VII in FIG. 6;

FIG. 8 shows a section according to line VIII--VIIIin FIG. 7;

FIG. 9 shows a section analogous to that in FIG. 8, but with referenceto another embodiment;

FIG. 10 shows a section according to line X--X in FIG. 1 to a largerscale.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a combination of a truck 1 with a trailer 2, whereby thetrailer 2 commonly consists of a frame 3 resting on two wheel sets atthe back and upon which is provided a floor 4 or superstructure.

These wheel sets, as is represented in detail in FIG. 2, hereby mainlyconsist of an axle 5 supported on suspension members 6 which areconnected to the frame 3 in a springy manner and wheels 7 fixed on theends of the axle 5.

The frame 3 mainly consists of two composed longitudinal members 8 andof cross members 9 mounted in between them.

The longitudinal members 8 are composed of two base struts 10 with aU-shaped section and two smaller connecting struts 11 which also have aU-shaped section, whereby both the base struts 10 and the connectingstruts 11 are pultruded struts or struts made by pultrusion fromcomposite material. By pultrusion, is meant a method known as suchwhereby a reinforcement formed of fibres or a tissue is moisturized withsynthetic material by immersion or spraying, and whereby the soakedfibres or the soaked tissue are subsequently pulled through a heatedextrusion device, after which the synthetic material cures. Compositematerial is synthetic material reinforced with fibres, such as polyesterreinforced with glass fibre. Also other synthetic materials or polymerscan be used. Instead of glass fibres, other reinforcement fibres can beused such as carbon fibres, aramid fibres and such.

As is represented in FIGS. 3 and 5, the base struts 10 with theirvertically erected cores are directed towards one another, and formingreceiving surfaces (for a trestle 12) with a distance between saidcores. As a result, the legs of the struts 10 are pointed laterallyoutward.

The connecting struts 11 are situated with their cores on top of and atthe bottom of the base struts 10 respectively, and thus with their legspointing towards one another.

The legs of these connecting struts 11 are glued to the backsides of thecores of the base struts 10, for example by a two-component glue such asepoxy.

The springy mounting of each suspension member 6 in relation to alongitudinal member 8 is carried out, as is represented in detail inFIG. 2, by a securing element, what is called a trestle 12, which issituated with its top part between the two base struts 10 of thelongitudinal member 8, at the position of an interruption 13 of theconnecting struts 11.

The trestle 12 has the shape of a tube which reaches to the top side ofthe longitudinal member 8 and which, under the longitudinal member 8, isbevelled on the back side.

The end of the trestle 12 situated between the base struts 10 is gluedto the cores of these base struts with two flat side walls.

A glue is selected which is similar to the glue used for composing thelongitudinal members 8.

Under the longitudinal member 8, the trestle 12 may possibly be widenedsomewhat to prevent the base struts 10 from shifting downwards withslightly protruding parts.

Right through the two base struts 10 and the trestle 12 may possibly beprovided with a bolt 14 upon its end is screwed a nut 15. This bolt 14is provided in a neutral place where there is no relative movement ofthe surfaces of the base strut 10 and the trestle 12 which are situatedagainst one another, and where the forces on the base struts 10 areminimal.

This bolt 14 does not serve to absorb forces, but it helps to prevent alateral shift of the trestle 12 in relation to the two base struts 10.Moreover, the bolt 14 keeps the trestle 12 and the base struts 10together, such that they cannot move during the curing of the glue.

The trestle 12 can be made of steel or aluminum, but it is preferablyalso made of composite material, for example by moulding it underpressure and heat, by way of what is called compressing moulding or thehand lay-up method. The compressing moulding technique consists inputting the polymer and the reinforcement fibres or a mat ofpre-impregnated fibres in a heated mould, and by subsequently pressingthe mixture of polymer and reinforcement in the required shape under alarge pressure of, for example, some 100 tons per m².

At the lower end of the trestle 12 is fixed a leaf spring 16, possiblyby hinges. At a distance from the trestle 12, the bearing 6 is fixed onthe leaf spring 16 by fasteners 17.

Between the suspension member 6 and a part of the trestle 12 situatedunder the longitudinal member 8 is provided a shock absorber 18, whereasbellows 19 are situated between the free end of the leaf spring 16 andthe longitudinal member 8 which are connected to a compressed air sourcein a manner which is not represented in the figures.

If necessary, the longitudinal members 8 can be reinforced at the bottomnear the axles 5 by auxiliary longitudinal members 20, as is representedin FIGS. 6 to 8.

These auxiliary longitudinal members 20 have the same section and aremanufactured in the same manner as the longitudinal members 8. Onlytheir length is much shorter.

The longitudinal members 8 and 20 are situated right underneath oneanother. The trestles 12 which are fixed to the longitudinal members 8extend between the two base struts 10 of the auxiliary longitudinalmember 20 and are glued to these base struts 10 in the same manner asthey are to the longitudinal members 8. The bellows 19 are erectedbetween the leaf spring 16 and the auxiliary longitudinal member 20.

The cross members 9 each consist of a round, tubular body 12 and roundflanges 22 on both ends as represented in FIGS. 5, 7 and 8. The tubularbody 21 is made of composite material, in particular by pulwinding orfilament winding.

Pulwinding is a variant of pultrusion, whereby one or several layers ofreinforcement fibres are wound on a mandrel and are soaked with polymerprior to and/or after the application, after which the whole is pulledthrough an extrusion part, after which the polymer cures.

Filament winding is a method whereby reinforcement fibres or ribbonssoaked with polymer are wound on a rotating mandrel or cylinder, afterwhich the polymer cures.

The flanges 22 are made as separate from composite material, preferablyby the above-mentioned compressing moulding technique, and they areglued to the ends of the body 21, preferably by a two-component gluesuch as epoxy. The connection of the flanges 22 to the body 21 isrounded on the side which is turned away from the end by a syntheticmaterial such as polyester.

The cross member 9 are glued with their flanges 22 to the core of a basestrut 10 of the two longitudinal members 8 and/or of the two auxiliarylongitudinal members 20 by a flexible glue, for example a two-componentglue.

In order to absorb shearing forces and to maintain the flanges 22 inplace during the curing of the glue, it is possible to further fix eachof the flanges 22 to the cores of the base struts 10 by four bolts 23and respective nuts 24.

If a cross member 9 is provided between the longitudinal members 8 atthe position of two trestles 12, the bolts 23 may replace theabove-mentioned bolt 14.

Also between the part of the two trestles 12 situated opposite oneanother which protrude at the bottom may be provided a cross member 9 inthe above-described manner, as is represented in FIGS. 6 and 7.

The obtained tubular construction of the composed longitudinal members 8provides a particular torsional strength. Thanks to the compositematerial and the gluing of the struts 10 and 11, these members areparticularly strong and light.

The cross members 9 do not only keep the two longitudinal members 8 inplace, but also absorb the torques of the frame 3 in the longitudinaldirection. The above-described cross members 9 are particularly fit forthis.

The top side of the trestle 12 situated between the base struts 10 of alongitudinal member 8, makes it possible for this trestle 12 to be gluedwith two vertical side walls and on both sides to the two base struts10, which results in a very large contact surface and prevents a load inone particular point on the longitudinal member 8.

All this allows for a significantly better connection of the trestle 12to the longitudinal member 8 than a plate which is fixed at the end ofthe trestle 12 and which would be fixed to the bottom side of thelongitudinal member 8 by glue, bolts or a combination thereof. Testshave proven that the latter mounting of the trestle 12 results in theconnection being torn after a while.

Not only are the longitudinal members 8 very strong and light, but alsothe springy connection of the trestles 12 is particularly strong. Partlythanks to this strong connection, it has become possible to usecomposite material for the struts 10 and 11.

The above-mentioned cross members 9 need not necessarily be providedwith flanges 22 at their ends.

They can be made according to another embodiment as represented in FIG.9, whereby their tubular body 21 is provided with a thickening 25 onboth ends. This thickened end has a sufficiently large surface to beglued tightly to the longitudinal members 8, either with or withoutadditional bolts.

According to this embodiment, the body 21 is obtained by pulwinding orfilament winding.

At the front, the above-described trailer 2 may contain, as isrepresented in FIG. 10, a plate 26 made of composite material which isglued to the bottom side of the two longitudinal members 8 and whichcarries a king pin 27 at the bottom with which the trailer 2 can beconnected to the pivoting platform 28 of the truck 1.

The present invention is by no means restricted to the above-describedpreferred embodiments, but covers all variations that might beimplemented by using equivalent functional elements or devices thatwould be apparent to a person skilled in the art, or modifications thatfall within the spirit and scope of the amended claims. springyconnection of the trestles 12 is particularly strong. Partly thanks tothis strong connection, it has become possible to use composite materialfor the struts 10 and 11.

The above-mentioned cross members 9 need not necessarily be providedwith flanges 22 at their ends.

They can be made according to another embodiment as represented in FIG.9, whereby their tubular body 21 is provided with a thickening 25 onboth ends. This thickened end has a sufficiently large surface to beglued tightly to the longitudinal members 8, either with or withoutadditional bolts.

According to this embodiment, the body 21 is obtained by pulwinding orfilament winding.

At the front, the above-described trailer 2 may contain, as isrepresented in FIG. 10, a plate 26 made of composite material which isglued to the bottom side of the two longitudinal members 8 and whichcarries a king pin 27 at the bottom with which the trailer 2 can beconnected to the pivoting platform 28 of the truck 1.

The present invention is by no means restricted to the above-describedpreferred embodiments, but covers all variations that might beimplemented by using equivalent functional elements or devices thatwould be apparent to a person skilled in the art, or modifications thatfall within the spirit and scope of the amended claims.

What is claimed is:
 1. A frame for a vehicle, comprising:at least twolongitudinal members (8) composed of composite material; at least twosuspension members (6); at least one axle (5) supported by thesuspension members (6); at least two connection devices (12, 16-19),each one of the connecting devices (12, 16-19) connecting one of thesuspension members (6) to one of the two longitudinal members (8); theconnection device (12, 16-19) including a connecting trestle (12), theconnecting trestle (12) having upper and lower ends and at least twostanding sidewalls; each of the longitudinal members (8) includingreceiving surfaces; the upper end of the trestle (12) positioned at thereceiving surfaces of each of the two longitudinal members (8); and theat least two standing sidewalls of the upper end of the trestle (12)glued to the receiving surfaces of each of the longitudinal members (8).2. The frame as recited in claim 1, wherein the connection device (12,16-19) includesa leaf spring (16) having at least two ends that isconnected at one of the ends to the lower end of the trestle (12),bellows (19) arranged between the other one of the ends of the leafspring (16) and each of the two longitudinal members (8), and a shockabsorber (18) arranged between one of the suspension members (6) and thetrestle (12).
 3. The frame as recited in claim 1, wherein each of thelongitudinal members (8) includes two base struts (10), each of the twolongitudinal members (8) includes two base struts (10), the upper end ofthe trestle (12) being inserted between said base struts (10) and gluedto the two base struts (10).
 4. The frame as recited in claim 3, whereineach of the longitudinal members (8) includes two base struts (10) andat least two smaller connecting struts (11), the upper end of thetrestle (12) is inserted between the two base struts (10) at a positionof an interruption (13) of one or more connecting struts (11).
 5. Theframe as recited in claim 1, wherein the trestle (12) is composed ofcomposite material.
 6. The frame as recited in claim 1, furthercomprising at least two auxiliary longitudinal members (20) composed ofcomposite material, each of the auxiliary longitudinal members (20)extends under each of the longitudinal members (8), the auxiliarylongitudinal members (20) positionable such that they may be either inor out of contact with the sidewalls of the trestles (12) that are gluedto the longitudinal members (8), when the sidewalls of the trestles (12)are in contact with the auxiliary longitudinal members (20) thesidewalls of the trestles (12) are also glued to the auxiliarylongitudinal members (20).
 7. The frame as recited in claim 1, whereinthe longitudinal members (8) are pultruded members.
 8. A frame for avehicle, comprising:at least two longitudinal members (8) composed ofcomposite material; at least two suspension members (6); at least oneaxle (5) supported by suspension members (6); a connection device (12,16-19) connecting each of the suspension members (6) to each of thelongitudinal members (8); each of the longitudinal members (8) includestwo base struts (10) and at least two smaller connecting struts (11),each of the base struts (10) having a U-shaped section, the, U-shapedsection of each of the base struts (10) including a core section; eachof the longitudinal members (8) are formed by gluing each of the atleast two smaller connecting struts (11) to the core sections of the twobase struts (10).
 9. The frame as recited in claim 8, wherein each ofthe connecting struts (11) having a U-shaped section, the U-shapedsection of each of the connecting struts (11) including legs, and thelegs are glued to the core sections of the base struts (10).
 10. A framefor a vehicle, comprising:at least two longitudinal members (8) composedof composite material; at least one axle (5) supported by suspensionmembers (6); a connection device (12, 16-19) connecting each of thesuspension members (6) to each of the longitudinal members (8); at leastone cross member (9) made of composite material, the cross member (9)having two ends and a tubular body (21) composed of a material made byfilament winding; and each of the ends of the cross member (9) glued toone of the longitudinal members (8).
 11. The frame as recited in claim10, wherein the cross member (9) includes two flanges (22) that areglued to the ends of the tubular body (21), the cross member (9)manufactured at a high temperature and pressure.
 12. The frame asrecited in claim 11, wherein the ends of the cross member (9), includingthe flanges (22) or a thickening (25), are fixed to the longitudinalmembers (8) by nuts (24) and bolts (23).
 13. The frame as recited inclaim 10, wherein the tubular body (21) includes a tubular wall, thetubular wall forms a thickening (25) at the ends of the cross member(9), the ends of the cross member (9) including the thickening (25) areglued to the longitudinal members (8).
 14. A frame for a vehicle,comprising:at least two longitudinal members (8) composed of compositematerial; at least two suspension members (6); at least one axle (5)supported by suspension members (6); a connection device (12, 16-19)connecting each of the suspension members (6) to each of the twolongitudinal members (8); a front portion having a plate (26) composedof composite material, said plate being glued to the two longitudinalmembers (8) and including a bottom; and a king pin (27) attached at thebottom of the plate (26) and configured to fasten the frame to atrailer.